Extended Data Fig. 3: Degeneration in dystrophic RCS retinas selectively hits recoverin-positive photoreceptors in the ONL.

a, Representative image of a retina section from n = 5 non-dystrophic RCS-rdy rats (4 months-old) stained with bisbenzimide to localize cell nuclei (red; left panel) and recoverin staining (white; right panel) to highlight both photoreceptor (pink arrows) and bipolar (green arrows) cell bodies. b, The frequency distribution of the cell diameter in non-dystrophic RCS-rdy retinas shows a bimodal pattern that allows distinguishing between photoreceptor (mean ± sem: 5.73 ± 0.78 µm) and bipolar (mean ± sem: 12.15 ± 0.14 µm) cell bodies. All 4 months-old dystrophic RCS groups, no matter whether treated (30 DPI) or untreated, show a single distribution of cell diameters around 12 µm, coinciding with that of bipolar cells in RCS-rdy. This shows that photoreceptors are dramatically decreased in all groups of RCS rats, while recoverin-positive bipolar cells are relatively unaffected. c, Pie charts representing the relative number of recoverin-positive photoreceptors and recoverin positive-bipolar cells expressed in percentage of the total cell body counts in control RCS-rdy retinas. The white areas in the RCS groups represent the percentage of photoreceptor loss. Sample size in b,c (experimental animals): n = 5 per experimental group (30 DPI). For each animal, images were acquired from corresponding fields in the various retinas by taking the injection site as reference point (2 slices/retina; 3 fields/slice). ONL, outer nuclear layer; INL, inner nuclear layer; GCL, ganglion cell layer. Scale bar, 50 μm.